Only the Super Bowl, presidential debates, the Oscars and a few other broadcasts attract the tens of millions of viewers that major advertisers, including movie studios and big consumer-product makers like PepsiCo Inc., long to reach.

New England Patriots&#8217- quarterback Tom Brady suffered a season-ending injury during yesterday&#8217-s game with the Kansas City Chiefs. After he left the game and before the extent of the injury was known, the TradeSport&#8217-s contract on whether the Pats would win the Super Bowl fell about 5 points (from 21 to 16). Then at about 6:30pm ET Yahoo Sports posted a story that he was done for the year and the price collapsed. It has now stabilized at about 8, so the injury experiment suggests that a healthy Brady was worth about 13 points in this market.[*] I hope his agent is paying attention.

[*] Possibly understates Brady&#8217-s value since there were already concerns about his health prior to the injury.